The present invention relates to a decelerating device, particularly for the moving part of a cabinet, comprising a cylinder filled with a fluid, preferably viscous, a rod sliding by means of a bushing for the closure of said cylinder and a piston sliding inside the cylinder and fitted with means for a calibrated through flow of the fluid.
European patent EP 1162 338 describes a decelerating device in which the head of the rod rests on the piston and, when actuated by an external force, pushes it towards the bottom of the cylinder. Resetting is obtained by means of a spring which actuates the piston in the direction of extraction, which in turn pushes the rod. The speed of extraction of the rod depends therefore on the force of the spring and on the viscosity of the fluid contained in the cylinder that flows through the piston.
In other known decelerating devices of this type, in which the rod is joined to the piston, the aim is that a slow braking stroke, in the direction of introduction of the piston, is followed by a fast return of the same, so that the moving part associated to the device, for example a draw that is braked in the direction of closing, is not instead equally hindered in the inverse movement of opening. This implies the adoption of devices with unidirectional valves on the piston, which complicate its production and make the device more costly.
German patent DE-OS 22 56 201 describes a decelerating device in which the reset spring is placed on the outside of the cylinder between the same and the front end of the piston rod. A second spring, placed inside the cylinder, has the sole function of regulating the change in compensation volume due to the introduction of the rod inside the cylinder and does not assist the movement of the same in any way.